Collapsible tank for convertible freight container

ABSTRACT

A freight container in the form of a tractor-trailer or intermodal container which is convertible for selectively carrying solid freight or bulk liquid freight including a housing, a plurality of collapsible tanks in the housing, liquid outlets in the tanks and conduits in communication with the liquid outlets located entirely within the housing and an opening in the housing proximate the outlets of the conduits. A liquid washing assembly is permanently mounted on the tanks both in the expanded and collapsed conditions of the tanks. Guide structure is provided in association with the frame of the collapsible tanks for guiding the frame in a perfectly vertical direction both when the tanks are being expanded and being collapsed. The upper and lower edges of the tank sides are bolted and clamped to their associated frames. Hot air ducts encircle the liquid conduits in the bases of the tanks.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part of application Ser. No. 08/933,605, filed Sep. 18, 1997, which is a continuation-in-part of application Ser. No. 08/654,855, filed May 29, 1996.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

BACKGROUND OF THE INVENTION

The present invention relates to an improved collapsible tank structure for a freight container which is convertible to selectively carry solid freight or bulk liquid freight.

By way of background, there are certain congealable liquids, such as printer's ink or chocolate, which are transported in freight containers. These liquids must be maintained at an elevated temperature to prevent congealing thereof. If the liquids are permitted to congeal, they will clog the liquid conduits. However, if the liquids are heated sufficiently to maintain their liquidity, congealing does not occur, and, further, the filling and emptying of the tanks is done more efficiently.

Also by way of background, there are variations in the placement of the liquid conduit associated with the opening in the bottom of a collapsible tank. These variations may be due to the requirement for different placements of the parts in different installations. However, it is necessary to insure that there is proper sealing of the tank liner and the gasket proximate the tank outlet. This requires that the bolts associated with the securing of the tank liner and the gasket be properly oriented regardless of the above-mentioned variations.

BRIEF SUMMARY OF THE INVENTION

It is the object of the present invention to provide an improved collapsible tank structure for a convertible freight container which includes a forced air heating system for maintaining liquidity of the tank contents.

Another object of the present invention is to provide an improved collapsible tank liquid opening conduit mounting and sealing structure. Other objects and attendant advantages of the present invention will readily be perceived hereafter.

The present invention relates to a collapsible tank comprising a collapsible tank comprising a flexible side, a bottom plate, a fluid opening in said bottom plate, a base underlying said bottom plate, a fluid conduit in said base and in communication with said fluid opening, and a hot air duct in said base.

The present invention also relates to a collapsible tank comprising a heating system for a collapsible tank comprising a collapsible tank, a flexible side on said collapsible tank, a bottom plate on said collapsible tank, a fluid opening in said bottom plate, a base underlying said bottom plate, a fluid conduit in said base, a first hot air duct in said base, a hot air heater, and a second hot air duct for effecting communication between said hot air heater and said first hot air duct.

The present invention also relates to a collapsible tank connection comprising a base, an outer rim on said base, a frame within said outer rim, a plurality of spokes extending between said outer rim and said frame, a tank opening within said frame, a first liquid conduit extending through said frame, a second liquid conduit in communication with said first liquid conduit and extending transversely thereto toward said tank opening and in communication therewith, a flange on said second conduit, an annular ring on said second conduit between said first conduit and said flange, a first annular plate having an outer portion welded to said ring, a second annular plate located on the opposite side of said first annular plate from said annular ring, a tank liner portion between said first and second annular plates, a gasket between said flange and said second annular plate, first bolts extending between said annular ring and said annular plate to clamp said gasket therebetween, and second bolts extending between said first annular plate and said second annular plate to clamp said tank liner portion therebetween.

The various aspects of the present invention will readily be perceived hereafter when the following portions of the specification are read in conjunction with the accompanying drawings wherein:

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a schematic plan view taken substantially along line 1--1 of FIG. 2 and showing certain internal structure of a convertible freight container in the form of a trailer which can selectively carry either bulk liquid freight or packaged solid freight;

FIG. 2 is a schematic side elevational view taken substantially along line 2--2 of FIG. 1 and showing the liquid tanks in a collapsed position to provide space for carrying solid freight;

FIG. 3 is a schematic view similar to FIG. 2 but showing the liquid tanks in an expanded position for carrying bulk liquid freight;

FIG. 3A is a schematic view taken substantially along line 3A--3A of FIG. 3 and schematically showing the internal piping arrangement within the freight container for filling and emptying the tanks;

FIG. 3B is a schematic fragmentary view taken substantially in the direction of arrows 3B--3B of FIG. 3A and showing an open door in the side of the freight container for obtaining access to the outlets of the piping associated with the tanks;

FIG. 3C is a fragmentary cross sectional view taken substantially along line 3C--3C of FIG. 3;

FIG. 4 is a schematic view taken substantially in the direction of arrows 4--4 of FIG. 1 and showing the track structure on the side wall of the container for guiding the tanks between vertically collapsed and expanded positions and also showing portions of the locking assembly for stowing the tanks;

FIG. 5 is a schematic view taken substantially along line 1--1 of FIG. 2 and showing the prior art cable and winch arrangement for expanding and collapsing the tanks;

FIG. 6 is a view taken substantially in the direction of arrows 6--6 of FIG. 3 and showing a top portion of the frame of the tank frame structure;

FIG. 6A is a cross sectional view taken substantially along line 6A--6A of FIG. 6;

FIG. 7 is a plan view taken substantially along line 7--7 of FIG. 3 and showing the bottom portion of the frame of the tank frame structure;

FIG. 8 is a view taken substantially in the direction of arrows 8--8 of FIG. 2 and showing the construction of the bottoms of the tanks and the bottom portion of the frame on which they are mounted and the piping associated therewith;

FIG. 9 is an enlarged fragmentary cross sectional view taken substantially along line 9--9 of FIG. 8 and showing the top and bottom frame portions for the collapsible tanks and the manner in which the flexible inner liner and the flexible outer shell are secured thereto and also showing in solid lines the rotatable spray ball washer secured to the tank hatch and also showing in dotted lines its position when the tank is collapsed;

FIG. 9A is an enlarged fragmentary cross sectional view of portions of FIG. 9 showing in greater detail the fastening connections between the flexible portions of the tank and the top and bottom portions of the frame associated therewith;

FIG. 9B is a greatly enlarged fragmentary view of a portion of FIG. 9A showing the connection between the upper portions of the flexible tank sides and the top portion of the frame;

FIG. 9C is a fragmentary cross sectional view taken substantially along line 9C--9C of FIG. 9 and showing a part of the bottom frame portion of each tank frame;

FIG. 9D is a fragmentary cross sectional view taken substantially along line 9D--9D of FIG. 9A and showing the detail of the band which secures the tank shell to the bottom frame portion;

FIG. 10 is an enlarged fragmentary cross sectional view taken substantially along line 10--10 of FIG. 8 and showing the piping structure in relationship to the supporting base portion of each tank;

FIG. 10A is an enlarged portion of FIG. 10 showing the outlet of the tank and the position of the spray ball in dotted lines when the tank is collapsed;

FIG. 10B is a view taken substantially in the direction of arrows 10B--10B of FIG. 10A;

FIG. 11 is an enlarged fragmentary cross sectional view taken substantially along line 11--11 of FIG. 8 showing the guide for guiding vertical movement of the bottom frame portion as it moves between its stowed and expanded positions;

FIG. 12 is a fragmentary cross sectional view taken substantially along line 12--12 of FIG. 8 and showing the safety strap structure associated with the bottom frame portion and the wall of the freight container;

FIG. 13 is a cross sectional view taken substantially along line 13--13 of FIG. 8 and showing the manner in which the two halves of the bottom frame portion are secured to each other;

FIG. 14 is an enlarged fragmentary cross sectional view taken substantially along line 14--14 of FIG. 8 and showing the interfitting connection between the bottom frame portion and the floor of the freight container which prevents movement therebetween in a direction longitudinally of the freight container;

FIG. 15 is an enlarged view of the track structure shown at the left side of FIG. 4;

FIG. 16 is an enlarged fragmentary view taken substantially in the direction of arrows 16--16 of FIG. 15 showing a portion of the winch and cable arrangement for raising and lowering the top and bottom frame portions associated with the tanks;

FIG. 17 is an enlarged fragmentary view taken substantially in the direction of arrows 17--17 of FIG. 15 and showing the pulley arrangement associated with the various cables connected to the bottom frame portions of the tanks;

FIG. 18 is a fragmentary enlarged view of the channel structure at the extreme left of FIG. 15;

FIG. 19 is a fragmentary cross sectional view taken substantially along line 19--19 of FIG. 18;

FIG. 20 is a fragmentary cross sectional view taken substantially along line 20--20 of FIG. 18 and showing the support bar in an extended position for supporting the bottom frame portion in a stored position and also showing the channel which guides the member which terminates the downward movement of the top frame portion and also showing the bar which limits downward movement of the top frame portion;

FIG. 20A is a fragmentary view taken substantially in the direction of arrows 20A--20A of FIG. 20;

FIG. 21 is a fragmentary enlarged cross sectional view taken substantially along line 21--21 of FIG. 20;

FIG. 22 is a fragmentary cross sectional view taken substantially along line 22--22 of FIG. 18 and showing a portion of the lower cam structure for pivoting the frame supporting bar to a stowed position;

FIG. 23 is a fragmentary cross sectional view taken substantially along line 23--23 of FIG. 18 and showing the latch for retaining the frame supporting bar in a frame stowing position;

FIG. 24 is an enlarged fragmentary view taken substantially in the direction of arrows 24--24 of FIG. 7 and showing the connections between the lower portions of the cable and the bottom frame portion;

FIG. 25 is a fragmentary cross sectional view taken substantially along line 25--25 of FIG. 24;

FIG. 26 is a fragmentary cross sectional view taken substantially along line 26--26 of FIG. 27 and showing the structure for stopping both upward and downward movement of the upper frame portion;

FIG. 27 is a fragmentary view taken substantially in the direction of arrows 27--27 of FIG. 26;

FIG. 28 is a fragmentary plan view of the top frame portion and portions of the tank structure associated therewith;

FIG. 29 is an enlarged fragmentary cross sectional view taken substantially along line 29--29 of FIG. 28 and showing the connections at the hatch cover of the tank;

FIG. 30 is a fragmentary cross sectional view taken substantially along line 30--30 of FIG. 28 and showing the structure for holding the hatch cover closed; and

FIG. 31 is a plan view of the piping of the spray washer assembly mounted on the two tank hatches of the two tanks mounted on each tank-carrying frame.

FIG. 32 is a side elevational view of an improved collapsible tank unit of the present invention;

FIG. 33 is a plan view taken substantially in the direction of arrows 33--33 of FIG. 32 and showing a portion of the top frame portion of the tank;

FIG. 34 is a view with parts omitted taken substantially along arrows 34--34 of FIG. 32 and showing a portion of the bottom frame portion of the tank;

FIG. 35 is a view, with parts omitted, taken substantially in the direction of arrows 35--35 of FIG. 32 and showing another view of a portion of the bottom frame portion of the tank;

FIG. 35A is a plan view of a reinforcing plate;

FIG. 36 is an enlarged fragmentary exploded view taken substantially along line 36--36 of FIG. 32 and showing various portions of the top frame portion of the tank;

FIG. 36A is a fragmentary enlarged portion of FIG. 36;

FIG. 37 is an enlarged fragmentary cross sectional view taken substantially along line 37--37 of FIG. 36 and showing a blind rivet connection used to secure the shell mounting band to its associated portion of the frame;

FIG. 38 is an enlarged fragmentary cross sectional view taken substantially along line 38--38 of FIG. 36 showing a stud connection utilized to secure the shell retaining band and the upper portion of the flexible shell to the upper frame portion of the tank;

FIG. 39 is an enlarged fragmentary view taken substantially in the direction of arrows 39--39 of FIG. 38 and showing the structure of the shell retaining band;

FIG. 40 is an enlarged fragmentary cross sectional view taken substantially along line 40--40 of FIG. 36 and showing a bolt connection which is utilized to secure the shell mounting band and the shell retaining band and the upper portion of the flexible shell to the rim of the upper frame portion;

FIG. 41 is an enlarged fragmentary exploded cross sectional view taken substantially along line 41--41 of FIG. 34 and showing the structure for securing the shell to the bottom frame portion of the tank;

FIG. 42 is an enlarged fragmentary view taken substantially in the direction of arrows 42--42 of FIG. 41 and showing the bottom retaining band for securing the bottom of the shell to the bottom frame portion;

FIG. 43 is an enlarged cross sectional view showing the parts of FIG. 41 in assembled condition;

FIG. 44 is a side elevational view of a freight container of the present invention taken substantially in the direction of arrows 44--44 of FIG. 46 but with the side of the freight container removed to expose the expanded collapsible tanks having forced air heaters for heating the conduits through which liquid material is passed to thereby prevent congealing thereof and to liquify any materials which have been congealed;

FIG. 45 is a view similar to FIG. 44 but showing one of the collapsible tanks in a collapsed position;

FIG. 46 is a view taken substantially in the direction of arrows 46--46 of FIG. 44 and schematically showing the liquid and hot air piping at the bottoms of the tanks;

FIG. 47 is a plan view of an insulating blanket which can be draped across the top and the ends of a pair of tanks as shown in FIG. 45 or which can be combined with another insulating blanket to cover the tops and outer ends of two pairs of tanks as shown in FIG. 44;

FIG. 48 is a fragmentary view, partially in cross section, taken substantially along line 48--48 of FIG. 44 and showing the heater and some of the conduits for supplying hot air and also showing the pump and some of the piping which is used for conducting fluid to and from the tanks;

FIG. 49 is a view, partially in cross section, taken substantially along line 49--49 of FIG. 48;

FIG. 50 is a fragmentary view taken substantially in the direction of arrows 50--50 of FIG. 49 and showing the connections on the inside wall of the freight container for receiving the ends of conduits for conducting hot air to the bases of the tanks and also showing the return air inlet;

FIG. 51 is an enlarged view taken substantially in the direction of arrows 51--51 of FIG. 45 and showing the hot air piping and liquid piping mounted in the bases of one pair of the tanks;

FIG. 52 is a fragmentary cross sectional view taken substantially along line 52--52 of FIG. 51 and showing the central structure at the base of each tank;

FIG. 53 is a fragmentary view taken substantially in the direction of arrows 53--53 of FIG. 52;

FIG. 54 is a fragmentary cross sectional view taken substantially in the direction of arrows 54--54 of FIG. 51 and showing the liquid pipe inside of the conduit for conducting hot air;

FIG. 54A is a fragmentary cross sectional view taken substantially in the direction of arrows 54A--54A of FIG. 51 and showing the liquid conduit and the hot air conduit construction which is located between the bases of adjacent tanks of a pair of tanks;

FIG. 55 is a fragmentary cross sectional view taken substantially along line 55--55 of FIG. 52 and showing apertures in the central rim portion of the base for permitting hot air to flow outwardly between the spokes of the base;

FIG. 56 is a fragmentary cross sectional view taken substantially along line 56--56 of FIG. 51 and showing structure at the base of the tank for permitting flow of hot air within the base;

FIG. 57 is a cross sectional view taken substantially along line 57--57 of FIG. 51;

FIG. 58 is a cross sectional view taken substantially along line 58--58 of FIG. 51;

FIG. 59 is a fragmentary cross sectional view taken substantially along line 59--59 of FIG. 51; and

FIG. 60 is a fragmentary exploded view of a portion of FIG. 52.

DETAILED DESCRIPTION OF THE INVENTION

Summarizing briefly in advance, the convertible freight container can selectively carry either bulk liquid freight or packaged solid freight. When it carries packaged solid freight, liquid tanks are maintained in a collapsed condition adjacent the roof of the freight container. When it is desired to carry bulk liquid freight, the tanks are expanded from a collapsed condition and moved so that they are supported on the floor and walls of the freight container. The piping for filling the tanks and draining liquid from the tanks is contained entirely within the freight container and access thereto is through an opening in the freight container. In certain embodiments, a washing assembly which is associated with the collapsible tanks is permanently mounted on the tanks. In accordance with certain embodiments, the tank base structure is of a configuration to occupy as little space as possible when the tank is in a collapsed condition to thereby leave more space in the freight container for solid freight. In accordance with the present invention, a heating system is associated with the collapsible tanks for preventing certain materials such as printing ink and liquid chocolate from congealing or for liquefying such congealed materials.

As is apparent from the drawings, the freight container 10 of the embodiment of FIGS. 1-31 includes numerous identical parts and numerous mirror image counterparts. However, in the interest of brevity, generally only one part will be described in detail and like numerals will be applied to both other identical parts and mirror image counterparts, which are obvious from the drawings.

The improved freight container 10 is schematically shown in FIGS. 1-5 in the form of a trailer. However, it will be understood that it can be in the form of a freight container of any type including an intermodal shipping container for transportation by ocean vessel, rail and truck. Also the convertible tanks may be installed in a straight truck or in a rail box car. Thus certain structural features described hereafter are equally applicable to a trailer and intermodal freight container and a straight truck and a box car. In fact the various features of the present invention can be installed in any type of freight-carrying body as set forth above, including an aircraft.

The freight container 10 includes a floor 11, a roof 12, and side walls 13 and 13'. It also includes a front wall 14 and a rear end 15 which has conventional doors 17. As noted above, the freight container 10 is in the form of a trailer having rear wheels 19 and a conventional stand 20.

A plurality of collapsible tanks 21 are mounted on frames 22 each consisting of top frame portion 23 and bottom frame portion 24. The tanks 21 are movable from a stowed condition proximate the roof 12 of the freight container (FIG. 2) to an expanded condition wherein they are supported on the floor 11 and sides 13 and 13' of the freight container (FIGS. 3 and 3C). The top frame portion 23 (FIG. 6) consists of two square frame members 25 coupled to each other by U-shaped brackets 27 which bridge frame sides 29 and are secured thereto by bolts 30. The bottom frame portion 24 is fabricated from two U-shaped portions 30 having sides 31 which are coupled to each other by U-shaped brackets 32 (FIG. 13) and bolts 33. The top and bottom frame portions 23 and 24 are fabricated from hollow rectangular tubular aluminum members to minimize weight to thereby permit the container to carry a larger payload.

Each collapsible tank 21 includes an inner flexible liquid impervious liner 34 and a flexible shell 35. Liner 34 is preferably fabricated of suitable sheet plastic, and shell 35 is also preferably fabricated of suitable sheet plastic. The types of plastic, namely, their composition and thickness will depend on the type of liquid which is to be contained therein. In the specific embodiment shown, the tanks are intended to carry corn syrup, and the liner 34 is a urethane composition which has walls which are 40 mils and a bottom 50 which is 100 mils thick, and shell 35 is a urethane composition which is 1/16 inches thick.

Each tank 21 includes a base 37 (FIGS. 8, 9 and 10) consisting of a plurality of aluminum spokes 39 (FIG. 8) of angle-shaped configuration (FIG. 9B) having horizontal legs 36 which rest on floor 11 when the tanks are in an expanded condition. Spokes 39 have their inner ends welded to the sides 40 (FIGS. 8, 9 and 10) of a box-like member 38 and their outer ends welded to aluminum circular frame member 41. A square plate 42 (FIGS. 9, 10, 10A and 10B) is welded to the inner surfaces of sides 40 of box-like member 38. An outlet plate 43 is bolted to plate 42 by a plurality of bolts 43'. Plate 43 has an outlet duct 44 welded thereto. The inner edge 50' (FIG. 10A) of bottom 50 of liner 34 is clamped between plates 42 and 43 by bolts 43' to provide a fluid tight connection between the plates 42 and 43. The outlet duct 44 (FIG. 10A) of plate 43 (FIG. 10A) is secured in fluid tight relationship to neck 46 of conduit 45 by a suitable flange type of clamp 48 with a gasket (not shown) between the flanges 46' and 48' of ducts 44 and 46, respectively. At this point, it will be appreciated that wherever a flange clamp is used, a suitable seal is associated therewith. Conduit 45 extends radially outwardly in base 37 and passes through an opening 51 in box side 40 (FIG. 10) and also passes through an opening 52 in member 41. A clamp 56' (FIG. 10) encircles conduit 45 and is secured to bracket 58' on frame member 41 for holding conduit 45 securely against movement. As can be seen from FIGS. 10 and 10A, conduit 45 has a flattened section 45a which merges into a cylindrical section 45b. This serves the purpose of permitting the base 37 to have relatively little height while still permitting the bottom of the tank to slope toward the outlet and also permitting the conduit 45 to have a standard three inch diameter capacity, which is the original diameter of the conduit 45 before it was flattened at section 45a. It is to be especially noted that the relatively little height of base 37 causes it to occupy relatively little space when the tank is stowed, which, in turn, provides greater volume in the freight container for packaged solid freight.

An aluminum dished plate 47 (FIGS. 9 and 10A) is welded to the tops of spokes 39 with its inner edge 46 welded to box sides 40 and its outer edge welded at 49 (FIGS. 9 and 9A) to outer frame member 41. Thus, dished plate 47 supports the bottom 50 of liner 34. Bottom 50 of liner 34 is a circular piece of plastic which is sealed to the cylindrical side 36 of liner 34 at joint 38. A circular plastic sheet 53 (FIGS. 9, 9A and 9B) has an upstanding cylindrical edge 56 (FIG. 9B) which is plastic welded or heat sealed to top edge portion 58 of liner 34 to provide a liquid and air-tight seal therebetween. The upper edge of liner 34 is formed into a bead 55. The upper edge of outer casing or shell 35 is also formed into a bead 57. Both beads are known as roped edges which are formed by enclosing a rope in the upper edge portion of each of the liner and shell and sealing it therein. A metal band 59 (FIG. 9B) is secured against side 36 of liner 34 and shell 35 below beads 55 and 57, respectively, by a plurality of circumferentially spaced blind fasteners 66 which are suitably spaced to press the liner and shell between it and circular frame member 54 and thus both provide a fluid tight seal between liner 34 and sheet edge 56 and also securely fasten the top of both the liner 34 and shell 35 to the circular frame member 54 which is welded to top frame portion 23. A cylindrical aluminum rod 60 (FIG. 9A) is attached as by welding to base member 41 and the lower portion of shell 35 passes around rod 60 and is clamped to base member 41 by a band 61. The lowermost portion of shell 35 is formed into a roped edge 62 which is located below band 61, and thus by virtue of the foregoing connection, the lower portion of shell 35 is securely held against member 41.

In FIGS. 9, 9A and 28-30, the top hatch 64 and associated structure are shown. A stainless steel cover 63 (FIGS. 9, 9B and 31) is secured across top frame portion 23, and it includes bent down edges 63' which lie against all of the outer sides of top frame portion 23. The top of each tank 21 is supported by a framework on top frame portion 23. More specifically, elongated struts 165 (FIG. 28) are secured to the inner surface of circular frame member 54 by brackets 166. Additional struts 167 are welded between frame member 54 and struts 165, and struts 168 are welded between spaced struts 165. A plurality of short diagonal struts 169 are welded between circular rim 170 and the corners of the square frame defined by struts 168 and the central portions of struts 165. Additionally gussets 171 are welded at the corners of frame 23, and additional struts 172 and 173 are welded into the positions shown in FIG. 28. All of the foregoing struts are hollow aluminum members which are rectangular in cross section.

The above described frame structure supports the hatch 64 and the structure which seals the top 53 of the inner liner 34 with the hatch. More specifically, hatch 64 includes an annular base 174 (FIGS. 29 and 30) with a plurality of circumferentially spaced threaded studs 175 extending upwardly therefrom at twenty degree intervals. The studs 175 extend through holes 177 in circular rim 170. The inner edge 179 of liner top 53 is held in fluid tight relationship between hatch base 174 and circular rim 170 when nuts 180 are tightened onto studs 175 with the inner edge of metal cover sheet 63 located under ring 181. An annular seal 182 is located at the upper edge of hatch 64, and a hatch cover 183 can be tightened onto seal 182 by a plurality of swingable bolts 184 which are swingable from clevis connections 185 on rim 181 with their upper threaded ends 187 being received in slots 189 in hatch cover 183 so that wing nuts 190 will bear on hatch cover 183 when the wing nuts are tightened. The hatch cover 183 has a vent 191 and an inspection port 192. Vent 191 serves the purpose of permitting air to be vented out of the tank 21 as it is being filled and permitting air to be vented into the tank as it is being emptied. Vent 191 is removable for cleaning and also has a baffle function which permits only air to pass therethrough. Inspection port 192 is a hinged cover which can be opened to permit viewing into the tank and permit the taking of samples of the liquid. A conventional spinner or spray ball and associated piping for washing the inside of tank 21 is permanently mounted on cover 183, as discussed in detail hereafter.

In FIG. 3A there is a schematic showing of how the conduits 45 of the tanks 21 are connected to conduits for emptying or filling of the tanks. The two conduits 45 of each pair of tanks 21 are connected to a conduit 64'. A valve arrangement is provided which permits any one tank 21 to be emptied or filled independently of any of the other tanks or they may be emptied or filled simultaneously. In this respect, a valve 65 is provided in each conduit 64'. A valve 67 is provided in each conduit 45 of the two central tanks 21. Therefore, if it is desired to empty or fill either one of the outermost tanks 21 only, the valves 67 are closed and either one of the valves 65 is opened. If it is desired to empty or fill only the two inner tanks 21, valves 65 are closed and either valve 67 is opened. If it is desired to empty or fill all tanks 21 simultaneously, all valves 65 and 67 are opened. The above-described piping may be modified to permit the various tanks 21 to carry different liquids simultaneously. In this respect, the Y 68 is eliminated and valves 65 and 67 are used to control flow relative to its respective tank 21.

At this point it is to be noted that the emptying or filling of the tanks 21 is from the extreme outer ends 69 of conduits 64'. In this respect, in order to empty or fill the tanks it is merely necessary to open door 70 in freight container side 13' so that access may be had to the conduits 64 and valves 65 and 67. Suitable hose connections (not shown) are thereafter merely connected to the outlets 69 of conduits 64 to thereby conduct the liquid to or from tanks 21. It is to be especially noted that all of the conduits for filling or emptying tanks 21 are completely enclosed within freight container 10, and thus there are no conduits exposed which can be damaged or onto which mud or ice can accumulate.

A structural arrangement is provided for lowering the tanks 21 from their stowed collapsed position of FIG. 2 to their expanded positions of FIG. 3 and for returning the tanks 21 from their expanded positions of FIG. 3 to their stowed collapsed position of FIG. 2. In this respect, a prior art electrically operated winch and cable arrangement is provided. More specifically, a winch 72 (FIGS. 4, 5 and 15) is mounted on wall 13 and it causes cable portion 73 to be pulled into the winch 72 in the direction of arrow 74 (FIG. 16) when the tanks are being raised or it causes the cable portion 73 to be let out in the direction of arrow 75 when the tanks 21 are being lowered. In this respect when the cable is let out in the direction of arrow 75, the frame 22 and tanks 21 mounted thereon will move downwardly by gravity. More specifically, cable portion 73 is connected to cable portion 77, the end of which is secured to winch housing 72 at 79. The central portion of the cable passes around pulley 80 which is mounted on member 81 connected to link 82. A plurality of cables 83, 84, 85 and 87 have their ends secured to link 82. Cables 83, 84, 85 and 87 lead to pulley arrangement 89 (FIG. 17) located on wall 13. At this point it can be seen from FIGS. 4 and 5 that there are two winches 72 and a cable system, such as described above, associated with each.

Cable 83 (FIG. 17) passes around pulley 90 and then passes around pulley 86 (FIGS. 5, 18 and 19) mounted on plate 88 on wall 13. Cable 83 thereafter passes around pin 84' (FIGS. 24 and 25) on lower frame portion 24 and then passes around a side of frame 24 and attaches to adjustable eye bolt 91 which is secured to bracket 92 on the inside of frame portion 24. Cable 84 passes around pulley 93 (FIG. 17), passes around pulley 94 on wall 13 and then down around pin 95 (FIG. 24) on frame portion 24 with its end attaching to I-bolt 97 (FIG. 24) secured to bracket 99 on the inside of frame portion 24. Cable 85 passes around pulley 100 (FIG. 17) and thereafter passes around pulley 101 (FIG. 5) fastened to side wall 13'. Cable 87 passes around pulley 102 (FIG. 17) and then around pulley 103 (FIG. 5) fastened to side wall 13' proximate roof 12. The ends of cables 85 and 87 are fastened to frame portion 24 in mirror-image relationship to the structure shown in FIGS. 24 and 25.

Guides 104 (FIGS. 7, 8, 11 and 24) are provided on bottom frame portions 24 to guide them in a precise vertical direction during raising and lowering of the tanks. In this respect, each guide 104 (FIGS. 7 and 11) is a cylindrical member which is mounted on plate 105 by a pair of U-bolts 107. Plate 105 has one end welded to bottom rim member 41 and the opposite end welded to the side of frame portion 24. As can be seen from FIG. 8, a guide member 104 is located on each opposite side of frame portion 24. The outer ends of guide members 104 ride in channels 109 in side walls 13 and 13'. In this respect, it is to be noted that channels 109 are only shown in wall 13, but it will be appreciated that there are mirror image channels in wall 13'. The guides 104 are known in the prior art. Each guide member 104 in wall 13 has a microswitch 106 associated therewith which is located in channel 109 for terminating the upward drive of winch 72 when actuated by guide 104 to prevent lower frames 24 from continuing movement beyond a predetermined height, thereby obviating the possibility that the winch will be caused to operate when the bottom frame cannot be raised any higher.

A safety strap construction 110 (FIGS. 8 and 12) is provided and is connected between a freight container wall and each side of bottom frame member 24, as known in the prior art, for the purpose of locking the bottom frame member against further movement in the event that its downward speed should exceed a predetermined value, as might occur if one of the cables attached to the bottom frame would break. More specifically, each safety strap 110 includes a body 111 which is secured to frame member 24 by bolts 112. A strap 113 is coiled within body 111 and the upper end of strap 113 is secured to bracket 114 located on wall 13 proximate roof 112. The safety strap structure 110 has conventional internal mechanism for locking strap 113 within its housing and thus achieving the above-mentioned purpose of stopping downward movement of the bottom frame 24 if the latter should exceed a predetermined speed. As can be seen from FIG. 7, a safety strap structure 110 is located on each side of the bottom frame portion 24.

As explained above, when the tanks 21 are in their expanded positions, the frame bottom portions 24 rest on the floor 11 of the freight container. However, structure is provided in association with the top frame portion 23 for both guiding it in a vertical direction as it moves between collapsed and expanded positions and for holding it at an elevation above the middle of the wall 13 (FIG. 3) when the tanks 21 are in their fully expanded condition. In this respect, brackets 117 (FIGS. 3C, 6, 26 and 27) are secured to upper frame portions 23. More specifically, each bracket 117 incudes a channel portion 119 having legs 120 with slots 121 therein. Bolts 122 extend through slots 121 in legs 120 and also extend through suitable apertures in frame portion 23. When bolts 122 are tightened, bracket 117 is firmly secured to upper frame portion 23. Bracket 117 includes a lower plate 123 having a hooked end 124. The foregoing is known in the prior art. In addition, an upright post 125 is welded to the top of plate 123 and a gusset 127 is welded to both plate 123 and post 125. Another gusset 129 is welded between the top leg 120 and post 125.

Channels 130 (FIGS. 2, 3, 15 and 18 are provided in side walls 13 and 13', and a bar 131 is welded in position in each of the channels. Bar 131 functions as a stop for hook plate 123. In this respect, the hook plate 123 of each member 117 rides in each channel 130 and when the plate 123 abuts bar 131 (FIG. 3C), the downward motion of upper frame portion 23 stops to thereby maintain the tanks 21 in the expanded positions of FIG. 3. The foregoing is known in the prior art. In addition, plates 132 are suitably fastened to the walls 13 and 13' proximate roof 12 (FIGS. 1, 2 and 3) and plates 132 are abutted by the ends 133 of bars 125 when the upper frame portions 24 are in their uppermost positions.

Structure is provided for locking the tanks 21 in their stowed position of FIG. 2. This structure is basically shown in prior art U.S. Pat. No. 4,735,457, which is incorporated herein by reference, but a description will be made of the present structure for the sake of completeness. When the tanks 21 have been pulled by the winch and cable arrangement to their stowed position of FIG. 2, the locking arrangement of FIGS. 18, 20, 21, 22 and 23 is utilized to lock them in position. More specifically, the locking structure includes a locking bar 135 which is moved to its extended position of FIGS. 18 and 20 perpendicular to wall 13 to bear against the underside of bottom frame portion 24 to maintain tanks 21 in their stowed position. Four locking bars 135 are associated with each lower frame portion 24. The locking bar 135 is fastened to a sleeve 137 which is pivotally mounted on shaft 139, and sleeve 137 is held against axial movement on shaft 139 by annular members 140 (FIG. 21) which are welded to shaft 139. An inclined strut 141 (FIG. 21) is welded between the underside of bar 135 and sleeve 137. In order to move bar 135 to the position of FIG. 20 for stowing the frame, lever 142, which is pivotally mounted at 143, is moved from its dotted line position to its solid line position. In order to do this, latch 144 is pivoted to its dotted line position to permit lever 142 to be moved from its dotted line position to its solid line position. The lower end 145 of rod 139 is pivotally mounted in lever 142 so that when the latter is moved toward its solid line position, rod 139 is raised. When it is raised, bar 135 moves from its dotted line position of FIG. 18 to its solid line position because the top of bar 135 rides along inclined cam surface 147 (FIG. 20A) which causes it to pivot outwardly to the solid line position shown in FIGS. 18 and 20. After lever 142 has been moved to its solid line position so that bar 135 is in its position of FIGS. 18 and 20, latch 144 is closed to retain lever 142 and bar 135 in their solid line positions. When it is desired to move bar 135 away from its extended position of FIG. 20 to release lower frame 24, latch 144 is moved to its dotted line position of FIG. 18, and lever 142 is pivoted downwardly to pull rod 139 downwardly. As the bar 135 is moved downwardly with rod 139, the strut 141 will engage inclined cam surface 149 to thereby pivot bar 135 to its dotted line position of FIG. 18 wherein bar 135 is received in recess 146. Rod 139 and lever 142 are housed in channel 150, and rod 139 is guided for vertical movement by angle bracket 148.

In FIG. 14 an arrangement is shown for locking the tank frames against movement longitudinally of the freight container when they are in their expanded positions of FIG. 3. In this respect, a toothed bar 152 (FIGS. 8 and 14) is bolted to frame member 41 by a pair of bolts 153. A companion toothed bar 154 is countersunk into the floor 11 of the freight container and is bolted thereto by bolts 155. When the tanks are in their expanded condition with the lower frame portion 24 resting on the floor 11 of the freight container, the toothed member 152 will mesh with toothed member 154 thereby preventing longitudinal movement of the lower frames 24 relative to the floor 11 of the freight container. This structure is known in the prior art.

A tank washer assembly 200 (FIG. 31) is permanently mounted on each pair of tanks 21 mounted on each frame 22. The various parts of the washer assembly are shown in FIGS. 3B, 9, 10A, 28, 29 and 31. More specifically, as can be seen from FIG. 31, one of the hatch covers 183 has a pipe 201 welded thereto and the other hatch cover 183 has a pipe 202 welded thereto. This is the only difference between the two hatch covers. A pipe 203 is connected between pipes 201 and 202 by flange clamps 204. Additionally, a pipe 205 is provided which is connected to pipe 202 by another flange clamp 204. Thus, if it becomes necessary to remove the cover 183 which has pipe 201 welded thereto, it is merely necessary to remove flange clamp 204 at the end of pipe 201 to thereby disconnect pipe 201 from pipe 203. Also if it is necessary to remove hatch cover 183 having pipe 202 welded thereto, it is merely necessary to remove flange clamps 204 on the opposite ends of pipe 202 to thereby disconnect pipe 202 from pipes 203 and 205. Pipe 205 is connected to pipe 207 by means of a swivel joint 209.

The conduit or pipe structure shown in FIG. 31 is used to supply liquid for washing tanks 21. In this respect, when it is desired to wash tanks 21, a hose 210 is installed on the end of pipe 207 when tanks 21 are in their expanded positions, such as shown in FIG. 3. The cleaning liquid is thus conducted through the piping of FIG. 31 to a conduit 211 in each tank 21. More specifically, one conduit 211 (FIG. 31) is in communication with pipe 202 and the other conduit 211 is in communication with pipe 201. The conduits 211 have a rotatable spray ball 212 mounted at the lower ends thereof for spraying the insides of tanks 21, and the washing liquid is discharged from tanks 21 through the piping shown in FIG. 3A at the bottoms of the tanks. The spray ball 212 sprays the liquid in a spherical pattern to thereby contact all portions of the inner surfaces of inner liner 34. The spray ball which is used may be of the type known as number 27500 which is manufactured by the Spraying Systems Company of Wheaton, Ill.

The above-described tank-washing assembly 200 is permanently mounted on tanks 21 both when the tanks are in an expanded condition and in a collapsed condition, thereby obviating the necessity to install the piping when it is necessary to wash the tanks. The only time that disassembly is required is when it is desired to remove the hatch covers 183, which is accomplished by unfastening the appropriate flange clamp or clamps 204 associated with the hatch covers. The position which conduit 211 and spray ball 212 occupy when the tank 21 is in an expanded position is shown in solid lines in FIG. 9, and the position that the spray ball occupies when the tank 21 is in a collapsed condition is shown in dotted lines in FIGS. 9 and 10A.

It is to be emphasized that while the foregoing description has been directed to a trailer type of freight container, most of the structural features described above are equally applicable to other types of freight containers, including but not limited to intermodal containers, straight trucks, box cars and aircraft.

It will also be appreciated that while the outlet of the piping, which is wholly contained within the described freight container, terminates proximate an opening in the side wall of the container, the piping can be modified so that it terminates proximate an opening in the front or rear walls or an opening in the floor of the freight container.

In FIGS. 32-43 a collapsible tank unit 225 is shown which comprises a pair of collapsible tanks 227 mounted on frame 229 consisting of a top frame portion 230 and a bottom frame portion 231. The tanks 227 which are mounted on frame 229 are movable between a stowed collapsed condition proximate the roof 12 of the frame container (FIG. 2) to an expanded condition where they are supported on the floor 11 and sides 13 and 13' of the freight containers (FIGS. 3 and 3C) as generally described above relative to tanks 21.

The top frame portion 230 comprises tubular sides 232 and 233 (FIGS. 33 and 37) which are hollow rectangular aluminum tubular members of the same cross sectional dimension. A frame member 235' of the same cross section as members 232 and 233 is welded to frame members 232. A pair of circular frame members or rims 234 (FIGS. 33 and 37) are welded to frame members 232 and 233 and to tubular frame member 235' at their areas of contact 237' (FIG. 36), and reinforcing plates 239 (FIGS. 35A, 36 and 37) are welded across the undersides of tubular members 233 and 234 and the undersides of tubular members 232 and 234 (FIG. 36) at 90° intervals, and to the undersides of tubular members 234 and 235' (FIG. 33). The top frame portion 230 also includes hollow tubular aluminum struts 240 welded between members 232 and 234 and also includes hollow tubular struts 241 welded between tubular members 233 and 234 and hollow tubular struts 242 welded between hollow tubular members 234 and 235'. Also, gussets 238' are welded between frame members 232 and 233.

The bottom frame portion 231 comprises two elongated hollow tubular aluminum members 243 (FIGS. 34, 35 and 43) of the same cross section as members 232 and 233. Members 243 have their opposite ends welded to circular sides or rims 244 of base 246 (FIGS. 35 and 43) at four areas 245. Reinforcing plates 247 (FIGS. 34 and 43), which are identical to plates 239 (FIGS. 35, 35A and 41), are also welded between frame members 244 and 243. Hollow tubular struts 249 are welded to arcuate plates 250 which are in turn bolted (FIG. 35) to sides 244 of base 246. The specific structure of the bottom frame portion 231 is shown in part in FIG. 35 wherein certain numerals are identical to those of FIG. 8 and they designate identical elements of structure. In the foregoing respect, the base 246 is identical to base 37 described above relative to FIGS. 8, 9 and 10, except for the manner in which the flexible tank sides 248 are attached thereto.

While not shown in FIGS. 32-43, except for the above-described structures of upper frame portion 230 and lower frame portion 231, and except for the improved manner in which the flexible collapsible sides 248 of tanks 227 are attached to upper frame portion 230 and lower frame portion 231, and except for the construction of flexible tank sides 248, all other parts of the collapsible tank structure are identical to the structure shown above in FIGS. 8, 9, 9C, 10, 10A, 10B, 28, 29 and 30. In addition, there has been a slight change in the subject matter of FIG. 31 in that conduit 205 has been detached from conduit 203 and conduit 203 has been closed at the point of detachment at 204. Additionally, a T has been inserted centrally in conduit 203 and conduit 210 has been attached to the T to supply liquid to conduit 203 through the T.

The side 248 of each collapsible tank 227 includes an inner flexible liquid impervious liner 251, which is fabricated of suitable sheet plastic, and shell 252, which is also preferably fabricated of suitable sheet plastic. The liner and shell each have a vertical lapped joint (not shown), but the vertical edges of the sheets can be joined in any suitable manner. In the specific embodiment shown, the liner 251 is a urethane composition which has walls which are 40 mils thick and is a polyester urethane film product of Bixby International Corp. and is designated Estane 58246. The shell 252 is a double ply of a PVC composition wherein each ply is 50 mils thick. It is a product of Seaman Corp. which is known as Model No. 9032 FRLTC-DC6. The shell is reinforced with polyester weft scrim which has great resistance to bulging due to the liquid pressure of the tanks 227, especially at the lower portions thereof.

As can be seen from FIGS. 37 and 38, the two plies 252a and 252b of shell 252 are fused to each other at their upper annular area 253 and their lower annular area 256, and ply 252a is bent over on itself at 254 and fused to itself after a roped edge has been made at 255. The roped edge is formed by enclosing a rope in the upper edge of the shell and sealing it therein by bending the edge of the shell back on itself as shown at 254. A circular plastic sheet 257, which is analogous to plastic sheet 53 of FIGS. 9, 9A and 9B, has an upstanding cylindrical edge portion 259 which is plastic welded or heat-sealed to the top edge portion 260 of liner 251, and the upper edge 261 of liner 251 is formed into a roped edge or bead. Thus, liner 251 and shell 252 both have roped edges 261 and 255, respectively, which serve their conventional purpose of preventing the liner 251 and shell 252 from moving downwardly out of their clamped position, which is described hereafter.

The upper edge of flexible tank side 248 is clamped to upper tubular member or rim 234 in the following manner.

Two tank side mounting bands 262 (FIG. 36A) are secured to circular tubular rim 234 by blind rivets 237 at spaced locations where plates 239 are located and by elongated fasteners, namely, nut and bolt assemblies 235 (FIGS. 36, 36A and 40), consisting of threaded bolts 236 and nuts 238. More specifically, as can be seen from FIGS. 36, 36A and 40, the nut and bolt assemblies 235 pass through the circular tubular member 234 and the shell mounting band 262 at spaced locations, and the blind rivets 237 (FIGS. 36 and 37) pass through the mounting band 262 at the spaced locations where plates 239 are located. There are two mounting bands 262 secured to rim 234, with each band having an extent of slightly less than 180°. There are two small gaps 263 (FIG. 36A) between the ends of the two bands 262. FIG. 36 shows a 90° portion of the mounting structure for the tank side 248, and it will be understood that the other 270° is identical, except for the areas where the two gaps 263 between the two bands 262 are located. The fact that the bolts 236 of the fastener assemblies 235 extend entirely through upper rim 234 provides a relatively strong joint in addition to facilitating the ease of assembly.

After the two tank side mounting bands 262 have been secured to rim 234 by blind rivets 237, and after bolts 236 have been inserted through holes 264 and 265 of rim 234, the shell 252 and liner 251 can be secured to bands 262 and rim 234. In this respect, the shell 252 and liner 251 have spaced holes 269 and 270 (FIG. 40), respectively, therein, and the bolts 236 are inserted through these holes. In addition, tank mounting bands 262 have a plurality of elongated fasteners, namely, threaded studs 271 welded thereto and extending outwardly therefrom (FIGS. 36, 36A and 38). The shell 252 and liner 251 also have spaced holes 272 and 273 (FIG. 38), respectively, therein through which studs 271 are inserted. After the shell 252 and liner 251 have been mounted on bolts 236 and studs 271, two retaining bands 274 (FIGS. 36A, 38, 39 and 40) are positioned adjacent the top portion 259 of liner 251 with the bolts 236 and studs 271 extending through holes 275 of the retaining band 274 (FIGS. 38, 39 and 40), and thereafter nuts 238 and 277 are tightened onto bolts 236 and studs 271, respectively, to tightly clamp the upper edges 254 and 259 of shell 252 and liner 251, respectively, between the two mounting bands 262 and the two retaining bands 274. Each retaining band is slightly less than 180° in extent, and there are two gaps 276 between the bands.

The lower edges of shell 252 and liner 251, which comprise the lower edge of the flexible tank side, are secured to base 246 of tank 227 in the following manner. The lower portion of shell ply 252b is folded over on itself at 277 (FIGS. 41 and 43) and sealed around plastic rope 279 to produce a roped edge. Also the circular tank liner bottom 280, which is analogous to circular tank liner bottom 50 of FIG. 9 and which is an impervious liner material such as the material of liner 251, is sealed at 281 (FIG. 43) to the portion of liner side 251 which is folded at 282 (FIG. 41). The circular bottom 280 is extended beyond liner side 251 and folded over on itself and sealed at 283 to form a roped edge in combination with plastic rope 284. The roped edges 277 and 283 comprise the lower edge of tank side 248 and they extend transversely thereto. After the roped edges 277 and 283 have been formed they are clamped between retaining band 285 (FIGS. 41, 42 and 43) and bottom plate 47 of base 246, bottom plate 47 being identical to dished bottom plate 47 of FIGS. 9 and 10A. The clamping is effected by elongated fasteners, namely, carriage bolts 287 which extend through holes 289 in retaining band 285 and holes 290 and 291 in roped edges 277 and 283, respectively, and through spaced holes 292 in dished plate 47. Nuts 293 are tightened onto bolts 287 to complete the clamping function.

An annular flexible plastic skirt 295 of the same material as shell 252 has an upper portion 297 which is heat-sealed to ply 252a of shell 252 and it has a lower roped edge 299. Skirt 295 covers the portions of the lower edge of the tank side 248 which is attached to base 246.

The tank unit 225 can be expanded and collapsed by the structure shown in FIGS. 15-27 or by any other suitable structure.

The forced hot air heating system (FIGS. 44-59) of the present invention is associated with collapsible tank units such as 225 each having a pair of tanks 227 described above relative to FIGS. 32-43 except for the base frames 310 and 310', which can be mirror-image counterparts. Frame 310 (FIG. 51) includes side rails 312 which are suitably attached to outer rims 313 of bases 311. Each base 311 has a plurality of spokes 314 which have their outer ends welded to outer rim 313 at 315 (FIGS. 51 and 56) and have their inner ends welded to cylindrical ring or frame 317 at 319 (FIGS. 51, 55 and 56). Each spoke 314 includes a vertical planar portion 320 which is welded at 321 (FIG. 56) to the bottom plate 322 of each tank, and it includes a horizontal flange 323 (FIGS. 51, 52, 55 and 56) which rests on the floor of the van when the tanks 227 are in an expanded condition. Bottom plate 322 is analogous to bottom plate 47 of the preceding embodiments. Additionally, each base 311 includes arcuate members 324 (FIGS. 51 and 56) which have their opposite ends welded to the vertical portions 320 of spokes 314 at 325 (FIG. 56). Ribs 327 (FIGS. 51 and 56) have first ends welded at 329 to arcuate members 324 and their opposite ends welded at 330 to outer rim 313 (FIG. 56).

In accordance with the present invention, forced hot air heating is supplied to the fluid conduits which are used for filling and emptying tanks 227. More specifically, a liquid conduit 331 extends between valve 332 (FIG. 51) and conduit 333 (FIG. 52) of the right-hand tank 227 (FIG. 1). There is an improved conduit mounting and sealing structure relative to the opening at the bottom of the collapsible tank. As can be seen from FIGS. 52 and 53, the end portion 334 of conduit 331 is coupled to tank 227 in the following manner. Conduit 333 has its lower end welded to end portion 334 of conduit 331 at annular weld 334' (FIG. 52). An annular flange 336 is formed integrally with conduit 333 (FIGS. 52 and 60), and it has a gasket-receiving groove 333' therein. A gasket 335' is located above annular flange 336, and annular plate 342 is located above gasket 334', and it has a gasket-receiving groove 343 therein. Annular ring 335 is circumferentially slidably mounted about conduit 333, and it has a plurality of apertures through which bolts 351' pass and are received in annular plate 342 to thereby clamp flange 336 to annular plate 342 with gasket 335' therebetween. Annular plate 342 and annular ring 335 can be oriented so that the apertures in annular ring 385 and the tapped bores in annular plate 342 for receiving bolts 351' are offset from the end of 334 of conduit 331 so that the heads of bolts 351' can be accessed by a wrench. This is necessary to accommodate variations in the placement of conduit 331. Bolts 344' extend through apertures in annular plate 337, which is welded to rim or frame 317, and are received in tapped bores in annular plate 342 to thereby clamp the edge 341 of tank liner 340 therebetween.

Liquid conduit 331 lies within hot air duct 344 (FIGS. 51 and 54). The portion of duct 344 in the right base 311 of FIG. 51 includes sides 345 having their upper ends welded at 347 (FIG. 54) to bottom plate 322 of tank 227. Sides 345 terminate at ring 317 and are welded thereto. Bottom plate 322 thus forms the top of duct 344. A U-shaped plate 349 has its side flanges 350 riveted at 351 to the lower edges of side plates 345 at suitably spaced intervals, and it extends into ring 317 as shown in FIGS. 51 and 52 to underlie conduit 331 and concentrate hot air along liquid conduit 331. A connecting conduit 352 (FIGS. 51 and 54A) has an upper inverted U-shaped portion 353 with tabs 354 which are riveted to outer rim 313 of base 311. Tabs which are similar to tab 354 fasten duct portion 352 to the outer rim 313 of the adjacent base 311. U-shaped portion 355 is riveted at 356 to the lower portions of inverted U-shaped member 353. Also, conduit 331 passes through suitable slots 358 (FIG. 54A) in rims 313 at the opposite ends of connecting conduit 352. Forced hot air duct 344 with fluid conduit 331 therein extends through open portions 357 and 359 in the vertical portions 320 and flanges 323 of spokes 314 of the left-hand tank base in FIG. 51. The portion of duct 344 in the right-hand rim 313 of FIG. 51 passes through opening 360 in arcuate member 324. Actually arcuate member 324 through which duct 344 passes consists of two separate arcuate portions 361 and 362, the edges of which are welded to the sides of duct 344. The portions 346', 347' and 348' of duct 344 are separate, and the ends of the side walls 345" (FIG. 59) of these duct portions, which are analogous to side walls 345 (FIG. 54), are welded to the sides 320 of the spokes 314 at 346". The other ends of sides 345" of portions 346' and 348' are welded to the rim 313. The bottom U-shaped portion 349" of these duct portions 346', 347' and 348' is a continuous member analogous to U-shaped member 349 of FIG. 54, and it extends between the spaced portions of rim 313 and has its ends welded thereto. The upturned flanges 350', which are analogous to flanges 350 (FIG. 54), are riveted to the side walls of duct portions 346', 347' and 348', as discussed above relative to FIG. 54. The flanges 350' pass through cutaway portions 351" in portions 320 of spokes 314.

The left-hand tank 227 (FIG. 51) includes a fluid conduit 363 which is housed within hot air duct 364. The inner end 334" of fluid conduit 363 is attached within cylindrical ring 317 in the same manner as described above in FIG. 52. The outer end of conduit 363 is in communication with valve 365. The hot air duct 364 has one end welded to the inner surface of outer rim 313 and the inner end welded to cylindrical ring 317. The central portion of hot air duct 364 passes between arcuate portions 366 and 368 and is welded thereto. Hot air duct 364 (FIGS. 51 and 57) is fabricated in the same manner as hot air duct 344 (FIGS. 51 and 54), and primed numerals on FIG. 57 represent analogous structure denoted by like unprimed numerals of FIG. 54, considering that ducts 344 and 364 of FIG. 51 are of like construction.

Hot air is supplied to ducts 344 and 364 in the following manner. Hot air is supplied, as will be described hereafter, to hot air duct 369 (FIG. 51) at its inlet 370. A duct 371 conducts hot air from duct 369 to duct 364. Duct 371 passes through suitable apertures 372 and 373 in spokes 314. Duct 369 passes through suitable apertures 374, 375 and 376 in the vertical sides 320 of spokes 314, and its end is in fluid tight contact with the side of hot air duct 344 at 377. Thus, the entire lengths of fluid conduits 331 and 363 are supplied with heated air to thereby prevent congealing of fluid therein or, alternatively, causing congealed fluid to be liquified. The apertures 372, 373, 374 and 376 are substantially the same as aperture 375 of FIG. 58. The ends of hot air ducts 344 and 364 at rim 313 adjacent valves 332 and 365, respectively, are not sealed so that hot air can pass through rim 313 at this location and provide heat to the adjacent valves.

It can thus be seen that heated air is supplied within both inner cylindrical rings or frames 317 (FIG. 52). The heated air is thereafter directed radially outwardly through apertures 380 in lower ring portion 317a, as shown by the arrows in FIG. 55. Each of the apertures 380 is located between a pair of spokes 314. As can be seen from FIG. 56, the arcuate members 324 and the ribs 327 are spaced above the lowermost flanges 323 of spokes 314 which thus permits the warm air to circulate as shown by arrow 381. The hot air seeps under outer rims 313 of bases 311 through parallel grooves 386 in the floor of the freight container, and these grooves underlie the entire bases 311 so that the hot air passes upwardly along the entire sides of tanks 227. Where the floor of the freight container is not grooved, rim 313 may have spaced apertures therein to permit hot air to diffuse outwardly and upwardly along the sides of the tanks.

The fluid is supplied to fluid conduits 331 and 363 in the following manner. A fluid pump 383 is housed within housing 384 (FIGS. 44, 45 and 48) and it is driven by a suitable hydraulic system (not shown). The source of fluid which is to be loaded into the tanks 227 is coupled by a suitable conduit to the inlet 384 of the pump. Conduits 385 lead from pump 383, and one conduit 385 is coupled to the inlet 387 of fitting 388 (FIG. 51) which is coupled to the conduits 331 and 363 of tanks 227. The other conduit 385 may be coupled to the other tank unit 225. As can be seen, the fitting 388 has a conduit 389 and a conduit 390 which are in communication with valves 332 and 365, respectively. Thus, tanks 227 can be placed in communication with pump 384 either simultaneously when both valves are open or selectively when one or the other of the valves is opened while the other is closed. While the fitting 388 is shown coupled to valves 332 and 365, it will be appreciated that fitting 388 can be removed and the conduit 385 leading from pump 383 can be connected separately to either valve 332 or valve 365.

The liquid can be supplied directly to valves 332 and 362 in a freight container such as 10' which does not have its own pump such as 383. In this event a conduit (not shown) leading an external pump extends through a doorway 398 shown in phantom in the side of the freight container 10'.

The hot air system operates in the following manner. A self-contained hot air heater 391 (FIGS. 48 and 49) is mounted within housing 384. This heater is of a conventional type which burns diesel fuel. The heater may be an ESPAR, Model D5LC, manufactured by Espar Heater Systems. A duct 392 has branches 393 which are fed from conduit 394, and ducts 393 are in communication with outlets 399 (FIG. 50) in the wall 397 of the freight container. Outlets 399 have U-shaped plates 400 adjacent thereto for receiving the annular rim 401 of a flexible corrugated hose 402 so that annular rim 401 is held between plate 400 and rear plate 403 with the neck 404 of hose 402 resting in arcuate recess 405 in plate 400. The opposite end 407 of hose 402 is suitably connected to the end 370 of hot air duct 369 (FIG. 51). A fan within hot air heater 91 forces hot air through hose 402 and into hot air ducts 364 and 344 which contain fluid conduits 363 and 331, respectively, hot air ducts 364 and 344 being supplied through hot air ducts 371 and 369, respectively, which are in communication with conduit 402.

The path which the hot air takes underneath the bases 311 of the tanks 227 of tank unit 225 was described above. This air will not only heat the metal base 322 of each of the tanks 227, but will also seep upwardly along the sides of tanks 227, thereby heating the sides of the tanks. The hot air will thus diffuse into the inside of the freight container 10', and it is returned to heater 391 through return air inlet 410 (FIG. 50) consisting of a plurality of perforations in plate 411. The return air passes into conduit 412 (FIG. 49) which leads to hot air heater 391. The diffusion of hot air to the area outside of rim 313 may occur through the channel-like grooves in the floor of the freight container, or apertures may be formed in the rim 313.

While not shown in the drawings, it will be appreciated that a tank unit 225 can be heated when it is in a stowed condition shown in FIG. 45, by merely connecting a flexible hose (not shown) to the inlet 370 of hot air conduit 369 (FIG. 51). Thus, there can be preheating of the liquid conduits while the freight container 10' is in transit.

To conserve the heat about tanks 227, an insulating blanket 415 (FIG. 45) is used with each tank unit 225. More specifically, insulating blanket 415 is made of any suitable material, and it contains suitable insulation and it has a central portion 417 which can overlie a tank unit 225 (FIG. 45) and it has end portions 419 and 420 which drape vertically over the ends of the tank unit 225. The insulating blanket 415 is of the approximate width of the freight container. The insulating blanket 415 has openings 421 which overlie the hatches at the tops of the tanks. To obtain access to the hatches there are covers 422 which may be snapped or hinged a the borders of openings 421.

In FIG. 45 it was shown how the insulating blanket 415 is used in conjunction with a single tank unit 225 when the latter is expanded while the other tank unit 225 is in a stowed condition. However, when both tank units 225 are expanded, as shown in FIG. 44, two insulating blankets 415 are used in the following manner. The left-hand blanket 415 has its end 419 draped vertically over the left end of the tank unit 225. The right-hand portion 420 which has pile fabric strips 423 thereon is mated with the hook fabric 424 at the left end of blanket 415, the central portion of which overlies the right-hand tank unit 225 with the end 420 of the right-hand blanket draping vertically over the right end of the right tank unit 225.

It can thus be seen that the improved collapsible tank is manifestly capable of achieving the above-enumerated objects, and while a preferred embodiment of the present invention have been disclosed, it will be appreciated that it is not limited thereto but may be otherwise embodied within the scope of the following claims. 

We claim:
 1. A collapsible tank comprising a flexible side, a bottom plate, a fluid opening in said bottom plate, a base underlying said bottom plate, a fluid conduit in said base and in communication with said fluid opening, and a hot air duct in said base.
 2. A collapsible tank as set forth in claim 1 wherein said hot air duct encircles said fluid conduit.
 3. A collapsible tank as set forth in claim 2 wherein said base includes an outer rim, an inner ring within said outer rim, said fluid opening being within said inner ring, and said hot air duct being in communication with said inner ring.
 4. A collapsible tank as set forth in claim 3 including openings in said inner ring.
 5. A collapsible tank as set forth in claim 3 including a second hot air duct in said base for conducting hot air to said hot air duct.
 6. A collapsible tank unit comprising first and sescond collapsible tanks, flexible sides on said collapsible tanks, first and second bottom plates on said first and second collapsible tanks, respectively, first and second fluid openings in said first and second bottom plates, respectively, first and second bases underlying said first and second bottom plates, respectively, first and second fluid conduits in communication with said first and second fluid openings, respectively, and first and second hot air ducts in said first and second bases, respectively.
 7. A collapsible tank unit as set forth in 6 wherein said first and second hot air ducts encircle said first and second fluid conduits, respectively.
 8. A freight container which is convertible for selectively carrying solid freight or bulk liquid freight comprising a freight container housing having a floor and a roof and walls, said housing containing at least one collapsible tank which can be selectively repeatedly converted between a collapsed stowed condition within said housing and an expanded condition for containing liquid cargo, a base on said tank, an outer rim on said base, a liquid outlet in said tank, a conduit in communication with said liquid outlet and located within said rim, and a hot air duct for conducting hot air into the space within said rim.
 9. A freight container as set forth in claim 8 wherein said hot air duct encircles said conduit.
 10. A freight container as set forth in claim 9 including an air heater mounted on said freight container, and a second hot air duct for effecting communication between said hot air duct and said air heater. 